Reducing-mill



E. B.-CAMPBELL.

fnsnucme MILL.

APPLICATION FILED FEB. H), 1919.

Patented Dec. 7, 1920.

INVENTOR.

'ldu anlfl 6 42 BY urom zr.

UNITED STATES PATENT OFFICE.

EDWARD B. CAMPBELL, or ST. LOUIS, mssounr, ASSIGNOB TO WILLIAMS PATENT CRUSHEIR. AND runvnarznn 00., on ST. LOUIS, mssoum, A coaroauron o1? MISSOURI.

REDUCING-MILL,

Specification of Letters Patent.

Patented Dec. 7, 1920.

To (M w ham it may concern:

Be it known that I, EDWARD B. CAMPBELL,

a citizen of the United States, residing at St. Louis, State of Missouri, have invented certain new and useful Improvements 1 n Reducing-Mills, of which the following is a specification. I

This invention relates to certain new and useful improvements in reducing mills, having especial reference to rotary pivoted hammers, the peculiarities of which will be hereinafter described and claimed.

The main object of my invention is the provisionof a slicing hammer having a long head, measured axially, and provided with legs separated from each other and from the adjacent ends respectively, whereby the long head is provided with a wider pivotal base than when one centrally disposed leg is used, as in my application on reducing mills of even date herewith. Another object is a simplified construction of hammer mounting whereby a divided compartment space inside the circle of the hammers is provided for the material being reduced.

In the accompanying drawing on which like reference letters indicate corresponding parts, Figure 1 represents a vertical sectional view across the shaft and housing of a mill illustrating my improvements; Fig. 2 a similar view,-the section being taken parallel to the shaft and giving a face view of the rotor; Fig. 3 a detailed perspective view of a forged hammer embodying my improvements; and Fig. 4: a similar view of my hammer as cast.

The letter A designates the housing of the mill having a hopper B, and a shaft C on which is keyed a disk D, having holes parallel to the shaft, in which are mounted hammer rods E that carry the legs F-F on the respective sides of the disk that divides the space within the cage into two compartments. The legs F are connected at right angles to a head G, so as to divide the length of said head substantially into thirds, and allow of connecting said legs to the head at substantially the middle third. The projecting ends of said head extend out laterally from the face of each leg at right angles thereto, and a distance practically equal to the space between the legs.

The legs and the head are of relatively greater width in the direction of rotation than thickness measured parallel to the pivotal axis. That is to say, the lesser dimension of both legs and head is presented to the material being reduced by said hammer, and tends to pass through the material with a slicing effect as opposed to a beating efiect. The space 9 between the said legs in the forged construction of hammer illustrated in detail in Fig. 3 has a single layer, while the projecting ends are doubled, since the long flat head is bent or doubled on itself at each end for one third of its length and then bent at right angles to the head, forming the legs as shown. The separated legs in this form of hammer give a wider pivotal base and a steadier support to the long straight head forming the main operative edge of the hammer.

As shown in Fig. 2, a single disk B is mounted in the central plane of the mill, providing two compartments within the cage and casing, and my form of hammer here shown with its projecting ends, affords ample space below the projecting ends or inside of the hammer circle formed thereby when rotating, for the material being operated on. The single layer or thickness of the straight head between the legs, eflects an improved slicing action on the material opposite the disk, while the thickness of the projecting ends is twice or more the width of the head.

In Fig. 4, the fiat bar construction of the forged hammer is followed in the cast steel form here shown, and the operative edge of the head G may be either plain, or otherwise formed, according to the material it is designed to operate on.

As shown in Fig. 2, double compartments within the cage, and clear except for the rotor shaft, is formed by the centrally disposed disk, and in each compartment the respective projecting end of the head of each hammer operates adjacent to the cage on the material within said compartment that is being ground. It has been found that the material fed to all reducing mills, tends to collect in the center rather than at the sides of the casing, and by locating this disk centrally as shown, the material is divided and more evenly spread over the length of the cage and hence is more efficiently reduced by the heads of the hammers. Also since only the lesser dimension of the projecting heads is presented to the ma terial being reduced, the power required to operate the rotor is correspondingly reduced. The middle portion ofthe cage opposite the disk is not prevented from receiving its proportion of material since a space is formed between the leg and opposite the central disk, in which material can be ground by the middle portion of the length of the bar head of the hammers.

I claim:

1. In a machine of the character described, a pivoted hammer comprising a pair of spaced shanks and a head connecting said shanks and extending on eachside beyond the same, the radial thickness of the head between the shanks being relatively less than that of the parts of the head beyond the shanks, whereby the ends of the head effect a crushing action and the part of the head between the shanks effects a slicing action.

2.*In a machine of the character described, a compound acting, crushing, two

way slicing hammer consisting of a pair of spaced shanks and a head of relatively thin radial dimension between the shanks and relatively thicker radial dimensions at the ends beyond the shanks, said shanks also having a thin slicing edge corresponding to the central portion of the head.

3. In a machine of the character described, a compound acting, crushing, two way slicing hammer consisting of a flat bar of relatively greater width than thickness bent upon itself to: form a head and two spaced'shanks, that part of the head between the shanks being of one thickness of the bar to slice material and those parts of the head beyond the shanks being of double thickness to grind material, the shanks being of a single thickness with their thin edge forward to effect a slicing action.

In testimony whereof I have aflixed my signature.

EDWARD B. CAMPBELL. 

